A clean-energy super PAC backed by a left-wing billionaire is spending heavily to unseat Republican Congressman Andy Ogles in Tennessee's 5th District primary, prompting warnings from allies of Donald Trump that Democratic money is attempting to interfere in GOP politics. Ogles, a vocal opponent of clean-energy subsidies, believes his advocacy against such measures has made him a target of well-funded outside groups seeking to replace him with a more industry-friendly Republican.

The Invest in Tomorrow Coalition, the super PAC involved, has already spent around a million dollars opposing Ogles while backing his primary challenger, Charlie Hatcher, Tennessee's former agriculture commissioner, and has since bought a further $700,000 in advertising. The group has raised $6.7 million so far this year, according to the article, underscoring the scale of resources being directed at the race, which is being closely watched as a test of energy-policy influence within Republican primary contests.